COVID-19 Outbreak Investigation in a Prison, Khon Kaen Province

Abstract

Prisons are environments that facilitate the transmission of communicable diseases, particularly Coronavirus Disease 2019 (COVID-19). In May 2024, a clustered outbreak was reported in a provincial prison in Khon Kaen, A disease investigation team conducted an epidemiological study to confirm the diagnosis and describe the outbreak. Among a total of 1,022 incarcerated individuals, 157 cumulative suspected cases were identified, yielding an attack rate of 15.36%. The female-to-male ratio was 1:3.13, and 24 inmates had underlying medical conditions. The most common presenting symptom was fever (63.06%). The age group with the highest proportion of cases was 58–62 years (25%). Laboratory testing confirmed SARS-CoV-2 Omicron variant B.1.1.529 sublineages: JN.1.18 (50%), JN.1 (20%), and JN.1.5 and BA.2.86.1 (10%). Association analysis demonstrated that sex was significantly associated with the presence of fever among cases (p-value < 0.05). The outbreak investigation indicated that transmission originated from close-contact visits by relatives, with initial infection among male inmates followed by spread to female inmates. Identified risk behaviors included close contact without face masks, sharing utensils and drinking glasses, and overcrowded sleeping areas with limited space. Based on the findings, key recommendations include visitor screening and mandatory mask use during visits, screening of inmates, health education on disease prevention and personal hygiene, and appropriate environmental sanitation within the prison.